How can I Include an installed module in customer RCP application?

Have you tried selecting the desired modules using the "Libraries" tab of the Project Properties window? Try this:
1. Right click on your NB platform app in the Projects panel and select Properties
2. Select Libraries on the project properties window
3. Find the modules that you want to include by looking under the various module suites that are present. 
4. Select the modules that you want to include in your application, resolve any dependencies, and then click OK.
5. Do a clean and build on your application.

After performing these steps, check to see if the desired modules are now present in your application.